Method of treating and utilizing gases.



No. 820,525 PATEN'IED MAY-15, 1906. I

I. W. CL SOHNIEW IND. METHOD OF TREATING AND UTILIZING GASES.

APPLICATION FILED JAN. 22. 1900.-

UNITED STATES Pr-YlllCX'l. ()l 'FI(, -E.

FREDERIC \-\'ILLL\-.\l cumulus si'nxum'ixn. or EYl-IHli'Fl. n-issunr- SETTS, ASSIGNOR To run rxrrico (our: .\.\'n dis .connix'r. or CHARLESTON, wnsr vnunxu, 1 mm nu'run' or n'ies'r run :m

lVlEITHtDD OF'TREATING AND UTILIZING GASES.

Specification of Letters Patent.

Patented May 15, 1906.

Application filed January 22. 1900. Serial No. 2,313.

a true and exact description, reference be ng had to the accompanying drawing, :which forms a part thereof.

My invention relates to the treatment and utilization of gases-generated in the process" of carbonizing fuels in closed externallyheat edretorts, and has for its object the saving and utilization of illuminants contained I in such gases, which have heretofore been to a large extent \vastedyand my invention consists, broadly speaking, in a process the first step of whichjs' accomplished by separating the'rieh and poor gases given off in the distillation process in substantially the manner described in m prior patent, No. 627,595, dated June 27, 1899, and then subjecting the fraction of the gases relatively poor in illuminantsto a treatment by means of which spective of the utilization subsequentlythe illuminants are removed from it for inde pendent use or sale. 0 My invention further consists in hereinafter-described modifications and additions to the general process indicated above.

In practice I have found it highly advantaeous to utilize the illun'iinants extract ed from the oorer fraction of gases for increasin the il uminating power and value of the ri her fraction of gas/b preference adding the illumin-ants extracte to such richer fraction without concentration or condensation;

but this process of utilizing the illun'iinant-s forms the subject-matter of my Patent No.

684,590, dated October .15, 1901, and my present invention isjdesigned to cover the process of recovering the illunnnants irremade of thenn As to the nature and distribution of illuminants I would state that bituminous coal. which is the most important raw material for the manufacture of gas, produces .coalgas when subjected to-dry' distillation in closed retorts' While the qua-lit} and illue mine-ting value of the varies considerably with the character of the coal, about sixtylive to eight per cent. of the lllllllllllzl-illl: value of the gas is due to lwnzoland its homologues and about twenty to thirtv-iive per cent, to the presence of hydrocarbons of tho olefine series, (etli -'lcnc and its homologucs.) A verylarge' proportion of benzol produced during the distillation ofthe coal remains in the gas after itleaves the maidensing plant. ()fthe total benzol yielded ninety per cent. was found in the gas and only ten per cent. in the tar. Again, a certain coal with-which I havc'workcd and subjected to dry distillation in a modern byproduct coke-oven yielded about ten thousand cubic feet of gals per gross ton, and of this there were approximately five thousand cubic feet (the first fraction) available as a surplus after applying the remaining, lire thousand cubic feet (the second fraction) for heating the coking-ovens. I alsoasccrtained that in the first fraction were containedabout sixt-y two per cent. of the total illuminants produced, including benzol and its homologues and ethylene and its homologues, while the second fraction contained aboutthirty-eight per cent, and it will be understood that my present process contem- )lates the utilization of the first or richer action for illuminating-gas or otherwise and the extraction from the second or poorcr fractionof the greater part of its illuminants before it is utilized for heating the cokingovens or for other purposes or allowed to go to waste.

' If the illuminants' contained in the richer and poorer fractions of the gas were present in the same proportion with respect to each other, a treatment tocxtrnct tlic lllllllllirilllis from the poorer fractons would be, to so tinleast, of probl'cnmtical value, because. while benzol and its homol-ogues can readily be extracted from gas, ethylene and its lower homologues are gases at ordinary tcmpcmturcs. which,practicallyspeaking,cam-lot lwextractcd from the gas; In the process of dry dist illation, however, by far. the largest portion of ethylene and its homologues are driven oil at lower temperature during the first stages of the operat on and are therefore found in the coxnn'ierc al utilization.

they constitute an iinportant percentage of the total illuininaiits, while in the poorer frac- '.t1on of the gases given off at higher temperai 5. t-ureduring the laterstage of the distillation these non-separable illuminantsform but an 'inconsiderable percentage, by far. the greater art consisting of benzol and its homologuesa bus, for example; I have found thatin the gas where thepoorer fraction showed 9.5

candle-power 8,8 of this was due to benzol end its ho1'nologues that is to say, of the total available candle-power 92.5 per cent. was,

. "tion, is one of considerable commercial value.

With regard to the removal of the illumi- 4 vnants from. the second fraction of the gas,I gs may state that several methods are applicable, depending upon the nature of the illu- .to beextracted. Several such "wn, and l donot wish to be I v .2111, Par c'ularginethofd eircept here such particular" method is expressly referred to in'the claims.- 7 "Generally: speak ing, the different methods in use are of two I charactersfirst, the cooling process accord 3 ingto which the benzol or its homologues are condensed by exposing the gas to low tern-- vperature, and, second, the absorption process", in accordance with which t-he benzol is extracted from the gasby exposingsuc-h gas 40' .to the action of oils or other materials having ct-he property of, absorbing benzoh- The taroil emp oyed may, for instance, conveniently be cteosote-oil-t'o wit, thefraction of coaltar distillation going over between 240 and 270 Centigrade. In this latter or absorption process. comparatively cold tar-oil is generally employed as the solvent, and in my preferred method I subject the ,second fraction of gas, preferably after treatment in the 5 0 condensingdiouse, to a scrubbing with tar-' oil in what I call the benzol -washer, the oil on entering the washer having a-losinp e y centage of benzol and on leaving it about twelve to fifteen per cent. of benzol. I then 5 Carry said oil into a benzol-still, in which the benzol or the greater part of it present is" thrownofl'as a distillate and afterward treatedin ,anv usual or convenient manner for i By preference,-howno ever, I subject the oil to a fractional distilla tion, first'driving off the bisulfid of carbon, which it has also absorbed and which can be readily separated before the benzol is driven M; i I richer fraction of the gasesin which fraction -s iii-iitingf myself. to; the em f C indicates the main through a pipe teases ofi',because the'boiling-point of the bisulfid of carbon is 47.0 centigrade, while the boilingpoint of benzol is 80.4 centigrade. The boiling-point of 'toluol is 111=O centigrade, and the boiling-point of Xylol is from 137.5 to 1421) centigrade. the benzol-still I cool the tar-oil down to the proper degree and again pass it through the benzolwasher, the process of extracting the benzol being thus conveniently made continuous.

Reference being now had to the drawing, which d'iagrannnatically represents a plant suitable for the practice of my inventioiu and in which is indicated a bank of coke-ovens,

A A Atindicating separate ovens, each provided, asshown', with two outlets for gas- Atter passing through one, (1, for the richer gas and the other, a, for

the poorer gas. These outlets are connected bypipcsa each having situated in it'a con trolling-valve (1 with either the rich-gas main (indicated at C) or the poor-gas main- (indicated at C.) Y

"B indicates the con lensing+l1ouse of the gas-plant, which I have indicated as divided into two separate systems B, inwhich the poor gasis treated,.and B in which thericher gas'is treated. The various'washmg and condens ng dev ces usually. employed in and washers E. v for the richer fraction of gas lead ng trom the condenser system B",

and C indicates a main .for the poorer fraction-of gas leading from the condenser system B to the benzol-washer, (indicated at F.) This washer has at its top a distributing de- ''ice for tareoil (indicated at F) and is filled with perforated trays (indicatedat F above its lowermost chamber F into which the pipe C enters.

(. leading from the top of the washer, is

such condensinghouses are indicated B f B, E, and E,-B'indicating S L1QC1OH.l)lOWeIS situated, as shown, between condensers B the conduit through which the poorer fraction of gas, robbed of its illuininants, i sconducted, either to heat the-ovens A or to any other point of-utilization or storage.

' f is the outlet-pipe tor'tar-oil, leading from the washer Fto a reservoir II.

G is a reservoir for cool tar-oil, connecting by a pipe 9 with the distributer F and is having situated in it a forcepump L, connected with theoil-reservoir K.

h is a pipe having in it .a' force-pump L, leading from the reservoir H to the bisulfidof-carbon still, (indicated at- O,) which still connects, by means of pipe-'h, withthe ben= zol-still I, and by means of the pipe 0 with the condensing-coil P situated in the con densing-tank I, p, and; 1), indicating inlet and outlet pipes for water. Coil I connects,

as shown, through a pipe p with a reservoir Q, in which the bisu'lfid of carbonis collected.- The benzol-still I is dividedintoseparate chambers in the usualxvay by partitions I having flanged openings, its-indicated at I,

. over which are secured flanged caps I. It is heated by a steannpipe Ifl'f'orining coils, as indicated at T in the lower chambers of the still,v T indicating the exhaust forthe steam.

If indicates the collecting-cha1nber for the J thropgh the pipe which leads to the reserpo'ir h, iron; which,,as already indicated, it is drawn into the supply-tank Gr.-

In operation the coal to be coked is char ed in the oven A A &e.,-and durin the ear 'e r stages of the coking operation whi e the ovens are giving oii rich gas the valves a areopened,

2 benzol-vapor at the top of the still from connecting the ovens with the main C the gases passing through the condensingehonse B and then main C to a place of'nse or storage. During the later stages of' the coking operation the valves aflconnectin'g the ovens with the main C are closed and-those connecting them w th the mainC opened, the poor gases passing through the condensinghouse B andthence by main O to the benzolswasher' F, through which they pass: up-

ward, escaping through main C by which they are conducted to the furnace-chambers (not shown) for. heating the' oven. The tar-'- oil for the washer F is supplied to it from tank G, flowing down through pipe g to the tions F to the chambers F 'a'nd thence by absorbed illuminants, is drawn through pipe h by pump Z, passing to the bisulfid-of can' hon still 0 and thence by pipe h to the -ben distributer F and passing through the parti- 'pipef to tank HQ From tank H the oil, with zol-still I, the bisiilfid of carbonidriven off in. still *3 passing by pipe 0 to the condenserworm P in cooling-tank P and thence a Y pipe 2 to storage -tank Q tilled off from the tar-oil in still I, escaping through pipe C to a place of use or storage,

The benzol is dis-- (not shown,) the oil passing down throngh storage-tank K, whence it is drawn-through pipe k by pump L to tank G. p I 1 Having now described my invention, what 'pipe '5 to the cooler J and thence. by pipe-y to I claim as new, and desire to secure byvLetters Patent, is

1. The method of utilizingthe gases generated in carbonizing carbonaceous fuels in closed externally-heated l'etorts, \vliich-consists in drawing oil' the richer gases generated in the first part oi the carbonizing process for separate uses as illuminating-gas orother-' wise.- said fraction of gas containing not only the larger percentage of total ilhnninants but V alsoa'larger relative percentage 'of the'inore gaseous illuminants, then drawing oii' the poorer gases generated during the later stages of the carbonizing operation into separate receptacles, said gaseshaving a larger relative; percentage of extractable ilhnninants and treating said poorer fraction for the removal ofits said more condensable illuminants.

2. Themethod of utilizing the gases generated in carbonizing carbonaceous fuels inclosed externally-heated retorts, which consists in drawing oil the richer'gases generated in the firstpart of theicarbonizing process for separateuses'as illuminating-gas or otherwise, said fra'ction of gas containing not only the larger ercentage of total' illuniinants, but also a a'rger relativepercentageot the more gaseous illuminants, thendrawin oiithe poorer gases generated during the later stages of the carbonizmg operation into sepa" rate. receptacles, said ases havin a larger relative percentage 0 extractab e illuminan'ts, treating said poorer fraction for the removal of its said more condensable illuminants, and then utilizing said. poorer asesafter their condensable illnminants have een extracted, for heating the gas gener atingree torts.

' 3. "The method of utilizing the gases generated. carbonizing carbonaceous fuels in closed externally-heated retorts, which @011- sists in drawing oii the richergases generated rod in the first part of. the carbonizing process for r separate 'uses asilluminating-gas or other- W se, said fracti j n of gas containing not only the larger per "hta e of total illunlinants, but also a larggli fre ative percentage ofthe' more gaseous lllilminants, then drawing off the poorer gases generated during the later stages of the carbonizing operation intoseparat-e receptacles, saidgases having .a larger relative percentage of extractableilluminants, washing said poorer gases with O1l 1Il order to separate the more condensable illunnnants and removing said extracted illuminants by distillation.

A. The method of utilizing the gases gener ated in carbonizing carbonaceous fuels in closed externally-heated retorts, which consists in drawingoff the richer gases generated .in, the first part of the ca-rbonizing process for separateuses as illuminating-gas or otherwise, said-'lraction of gas containing not only I the lar er percentage of total illuminants but also a Targer relative percentage of the more gaseous illuminants theh draWin q off the poorer gases generated during tTlQlfittGl stages of the carbonizing operation into sepa-- 'rate receptacles, sald gases havln' h larger relative ercentag'e of extractab e illuminants, su ectmg sold-poorer gasesto a-condensing and washing treatmen't in order toremove'lits more extractable illuminant's'. I 

